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Need help with FITS -



 
 
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  #1  
Old January 6th 07, 10:10 AM posted to sci.astro.ccd-imaging
jerry
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Posts: 1
Default Need help with FITS -

Is anyone here familair with fits image reading, conversion, etc?
tia

Jerry

  #2  
Old January 6th 07, 04:19 PM posted to sci.astro.ccd-imaging
Chris L Peterson
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Posts: 10,007
Default Need help with FITS -

On Sat, 06 Jan 2007 03:10:27 -0600, jerry wrote:

Is anyone here familair with fits image reading, conversion, etc?
tia

Jerry


What is it you want to do? There are dozens of programs that can be used
to read, write, and display FITS files. If you're looking to spin
something yourself, the easiest way is to use the freely available
CFITSIO library, at http://heasarc.nasa.gov/fitsio/fitsio.html . This is
written by the same people who maintain the FITS standard.

_________________________________________________

Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com
  #3  
Old January 7th 07, 07:35 AM posted to sci.astro.ccd-imaging
jerry warner
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Posts: 1
Default Need help with FITS -



Chris L Peterson wrote:

On Sat, 06 Jan 2007 03:10:27 -0600, jerry wrote:

Is anyone here familair with fits image reading, conversion, etc?
tia

Jerry


What is it you want to do? There are dozens of programs that can be used
to read, write, and display FITS files. If you're looking to spin
something yourself, the easiest way is to use the freely available
CFITSIO library, at http://heasarc.nasa.gov/fitsio/fitsio.html . This is
written by the same people who maintain the FITS standard.



Thanks for replying Chris. I have no working knowledge of
fits files. Im trying to get v-spec running. V-spec requires fits
image files. I need to convert jpegs and bmp files into FITS -
somehow. I downloaded a converter from NASA but it asks
for two file pathways? I dont even know where to begin.

Everyone here avoids these issues by using canned software
like aip4.win ? which evidently can convert files formats at will.
One guy puts his jpegs or bmps into aip4 and out comes fits files
which he can then read with a fits reader or processes with v-spec.

I dont understand what two pathways for a single fits file
means? Im missing something basic ...

The whole issue is to be able to take whatever file format different cameras
out put and be able to convert them into fits files I can
then use with V-spec or any other software requiring fits image
files. There are 8 bit, 16 bit, 32 bit type files ..... Im lost!

Thats the problem.
Jerry


..

_________________________________________________

Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com


  #4  
Old January 7th 07, 08:21 AM posted to sci.astro.ccd-imaging
Chris L Peterson
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Posts: 10,007
Default Need help with FITS -

On Sun, 07 Jan 2007 00:35:43 -0600, jerry warner
wrote:

Thanks for replying Chris. I have no working knowledge of
fits files. Im trying to get v-spec running. V-spec requires fits
image files. I need to convert jpegs and bmp files into FITS -
somehow. I downloaded a converter from NASA but it asks
for two file pathways? I dont even know where to begin.


I don't know what converter you are using. I'd guess that the two paths
it's asking for are the source file and the destination file. So if you
have a source IMG.BMP, the converter probably expects something like
CONVERT IMG.BMP IMG.FITS.


Everyone here avoids these issues by using canned software
like aip4.win ? which evidently can convert files formats at will.


Quite a few astronomical imaging apps can convert between formats.
Converting from JPEG to FITS is not common, since JPEG files are fairly
useless for any sort of analysis, and that's usually why you want FITS.
If you intend to do analysis, you should try to avoid JPEG files. BMPs
are better, but they are only 8-bit (or 8-bit per color channel), which
is often very limiting. Something with more bits is better. Are you
using a digicam of some sort? If it has RAW, that is often 10-12 bits.

FITS is generally the native file format for astronomical cameras, or
for astronomical software that interfaces with cameras.

If you have Photoshop, you could download a free plugin that lets you
save in FITS format, so you could use that for conversion. Another
option is IRIS, http://www.astrosurf.com/buil/us/iris/iris.htm . This is
a powerful image processing program, although it's hard to use (careful,
it has a retarded installer that will try to place the program in your
root directory). But it can read JPEGs and BMPs and write FITS.

_________________________________________________

Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com
  #5  
Old January 7th 07, 08:32 PM posted to sci.astro.ccd-imaging
Carsten A. Arnholm
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Posts: 84
Default Need help with FITS -

jerry warner wrote:
Chris L Peterson wrote:

On Sat, 06 Jan 2007 03:10:27 -0600, jerry wrote:

Is anyone here familair with fits image reading, conversion, etc?
tia

Jerry


What is it you want to do? There are dozens of programs that can be
used to read, write, and display FITS files. If you're looking to
spin something yourself, the easiest way is to use the freely
available
CFITSIO library, at http://heasarc.nasa.gov/fitsio/fitsio.html .
This is written by the same people who maintain the FITS standard.



Thanks for replying Chris. I have no working knowledge of
fits files. Im trying to get v-spec running. V-spec requires fits
image files. I need to convert jpegs and bmp files into FITS -
somehow. I downloaded a converter from NASA but it asks
for two file pathways? I dont even know where to begin.


Hi,

There are lots of image converters around. I think vspec wants unsigned 16
bit Fits, something you can create using my ImageTOOLSca
http://arnholm.org/astro/software/ImageTOOLSca/ . It will take jpeg and
bmp as input and write FITS, but I would not recommend such conversions from
8bit to 16bit for serious work, better to work with original Fits.

Clear skies
Carsten A. Arnholm
http://arnholm.org/
N59.776 E10.457

  #6  
Old January 8th 07, 07:50 AM posted to sci.astro.ccd-imaging
Big Mak Attack
external usenet poster
 
Posts: 3
Default Need help with FITS -



Chris L Peterson wrote:

On Sun, 07 Jan 2007 00:35:43 -0600, jerry warner
wrote:

Thanks for replying Chris. I have no working knowledge of
fits files. Im trying to get v-spec running. V-spec requires fits
image files. I need to convert jpegs and bmp files into FITS -
somehow. I downloaded a converter from NASA but it asks
for two file pathways? I dont even know where to begin.


I don't know what converter you are using. I'd guess that the two paths
it's asking for are the source file and the destination file. So if you
have a source IMG.BMP, the converter probably expects something like
CONVERT IMG.BMP IMG.FITS.


Oh well if thats all it means, that has to be it. No instructions came with
the software I pulled off a nasa site and no labeling of windows on the
software face except Path-1, Path-2.


Everyone here avoids these issues by using canned software
like aip4.win ? which evidently can convert files formats at will.


Quite a few astronomical imaging apps can convert between formats.
Converting from JPEG to FITS is not common, since JPEG files are fairly
useless for any sort of analysis, and that's usually why you want FITS.
If you intend to do analysis, you should try to avoid JPEG files. BMPs
are better, but they are only 8-bit (or 8-bit per color channel), which
is often very limiting. Something with more bits is better. Are you
using a digicam of some sort? If it has RAW, that is often 10-12 bits.


Im using a Tucam, and Sac-IV, and may be using several older digital cameras
like the Kodak DC-4 etc... What I have however are many jpeg files sent to
me by others I want to process to
send back. I should get these people to send in some other format.




FITS is generally the native file format for astronomical cameras, or
for astronomical software that interfaces with cameras.

If you have Photoshop, you could download a free plugin that lets you
save in FITS format, so you could use that for conversion.


I have Photoshop and can do this. I wasnt aware there was a
fits plugin.



Another
option is IRIS, http://www.astrosurf.com/buil/us/iris/iris.htm . This is
a powerful image processing program, although it's hard to use (careful,
it has a retarded installer that will try to place the program in your
root directory). But it can read JPEGs and BMPs and write FITS.


I have IRIS but have never activated it because it seemed so
complicated. I think the plugin for Photoshop may solve this.
But now that I understand "two pathways" I may have the NASA
converter up quick - I am sure you have to be right about this.

What confused me about the NASA software with "two pathways" was their brief
instructions mentioned two or more "file extensions". I open the software
and saw two windows for two pathways ...
and blocked mentally.

Thank you Chris. I think Im there now.
Jerry






_________________________________________________

Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com


  #7  
Old January 8th 07, 08:03 AM posted to sci.astro.ccd-imaging
Big Mak Attack
external usenet poster
 
Posts: 3
Default Need help with FITS -



"Carsten A. Arnholm" wrote:


Hi,

There are lots of image converters around. I think vspec wants unsigned 16
bit Fits,


OK, this helps to know. This nails down what version of FITS
I need for v-spec. I was very unsure about that.

something you can create using my ImageTOOLSca
http://arnholm.org/astro/software/ImageTOOLSca/ . It will take jpeg and
bmp as input and write FITS, but I would not recommend such conversions from
8bit to 16bit for serious work, better to work with original Fits.


Believe me I understand this. This is not "serious" work. Not yet
at least. This is simply to get jpeg and bmp files from Tucam and
and other simple cameras into the proper fits format (unsigned
16 bit fits!) so I can do some low level processing and generate
a graph. ___ I am not sure what "unsigned" 16 bit fits means? Is
there a "signed" 16 bit fits?

I also have people send me jpegs they want me to make a spectrum for them from.
If I could use v-spec I could add a graph.

For serious work I fully understand the st7 etc and wares like ccdsoft have the
option of saving in fits, direct to v-spec. But I
dont personally do not own one of those cameras and am new to v-spec and have
never worked with FITS at all. (Maybe some
day I will win the lotto and can afford an st9 or a Canon...)

Thanks very much for this help -
Jerry









Clear skies
Carsten A. Arnholm
http://arnholm.org/
N59.776 E10.457


  #8  
Old January 8th 07, 04:29 PM posted to sci.astro.ccd-imaging
Carsten A. Arnholm
external usenet poster
 
Posts: 84
Default Need help with FITS -

Big Mak Attack wrote:
"Carsten A. Arnholm" wrote:
Hi,

There are lots of image converters around. I think vspec wants
unsigned 16 bit Fits,


OK, this helps to know. This nails down what version of FITS
I need for v-spec. I was very unsure about that.

something you can create using my ImageTOOLSca
http://arnholm.org/astro/software/ImageTOOLSca/ . It will take
jpeg and bmp as input and write FITS, but I would not recommend such
conversions from 8bit to 16bit for serious work, better to work with
original Fits.


Believe me I understand this. This is not "serious" work. Not yet
at least. This is simply to get jpeg and bmp files from Tucam and
and other simple cameras into the proper fits format (unsigned
16 bit fits!) so I can do some low level processing and generate
a graph.


Hi,

If webcam capture is your starting point, then they typically deliver AVI
video files originally. My program can also convert directly from AVI to 16
bit unsigned FITS, optionally also performing gamma adjustment at the same
time (ref also. http://preview.tinyurl.com/y27kb7)

___ I am not sure what "unsigned" 16 bit fits means? Is
there a "signed" 16 bit fits?


Yes. It refers to how integer numbers are interpreted on the computer.
Integers can be with or without sign, the unsigned ones are all positive
(zero inclusive) while the signed ones can be both negative and positive.
Fits files can contain both types of integers (unfortunately). The ranges
these variants represent are slightly different. The way FITS files are used
my many programs is a bit messy, so often you have to deal with the
signed/unsigned issue, i.e. you may have to know the requirement of each
program to get it right.

I also have people send me jpegs they want me to make a spectrum for
them from. If I could use v-spec I could add a graph.


It is possible to convert to FITS, but not optimal as mentioned. Be aware
that normally, JPG files are in colour but FITS files are mostly monochrome
(grayscale). My program can generate both monochrome and colour FITS from
other formats, but vspec will expect monochrome only.

For serious work I fully understand the st7 etc and wares like
ccdsoft have the option of saving in fits, direct to v-spec. But I
dont personally do not own one of those cameras and am new to v-spec
and have never worked with FITS at all. (Maybe some
day I will win the lotto and can afford an st9 or a Canon...)

Thanks very much for this help -


You are welcome!

Clear skies
Carsten A. Arnholm
http://arnholm.org/
N59.776 E10.457


  #9  
Old January 8th 07, 04:34 PM posted to sci.astro.ccd-imaging
Chris L Peterson
external usenet poster
 
Posts: 10,007
Default Need help with FITS -

On Mon, 08 Jan 2007 00:50:14 -0600, Big Mak Attack
wrote:

Im using a Tucam, and Sac-IV, and may be using several older digital cameras
like the Kodak DC-4 etc... What I have however are many jpeg files sent to
me by others I want to process to
send back. I should get these people to send in some other format.


To the extent you have control over it, make sure that you have
streaming compression disabled, and if possible use a capture program
like K3CCD that can save directly to lossless formats. K3CCD can even
save to FITS directly.


I have Photoshop and can do this. I wasnt aware there was a
fits plugin.


Try this: http://www.astroshed.com/fitsplug/fitsplug.htm . The old
shareware version is all you need.

_________________________________________________

Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com
  #10  
Old January 9th 07, 07:01 PM posted to sci.astro.ccd-imaging
Malcolm Currie
external usenet poster
 
Posts: 1
Default Need help with FITS -

Carsten A. Arnholm wrote:

___ I am not sure what "unsigned" 16 bit fits means? Is
there a "signed" 16 bit fits?


Yes. It refers to how integer numbers are interpreted on the computer.
Integers can be with or without sign, the unsigned ones are all positive
(zero inclusive) while the signed ones can be both negative and positive.
Fits files can contain both types of integers (unfortunately). The ranges
these variants represent are slightly different. The way FITS files are
used my many programs is a bit messy, so often you have to deal with the
signed/unsigned issue, i.e. you may have to know the requirement of each
program to get it right.


16-bit integers are signed in FITS, i.e. the values stored in the image
array go from -32768 to 32767. The equivalent of unsigned, i.e. from 0 to
65535, can be achieved using the scaling header keywords called BSCALE and
BZERO set to 1 and 32768 respectively. Unsigned value = BSCALE * (FITS
value) + BZERO. I don't know if it is still the case, but there was a
time when some CCD-camera manufacturers for the amateur market thought that
FITS was unsigned, leading to confusion if images were exported to kosher
FITS readers.

Malcolm Currie
 




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